Medical professionals have long recognized the need for surgical instruments that can utilize a multitude of interchangeable tools. What has been needed but heretofore unavailable are surgical instruments that are compatible for use with detachable and interchangeable tools that incorporate universal connectors that establish interchangeability with a multitude of surgical tools and devices. A further need includes tools that incorporate failsafe features that ensure that the instrument fails in a particular way to minimize the risks of patient injury. Such a predetermined failure method ensures that no instrument fragments enter the patient upon failure of the instrument. Yet another shortcoming of the prior art instruments has been their failure to shroud and electrically insulate predetermined portions of the tool, as well as to shield surrounding tissue from inadvertently becoming pinched by the moving elements of the tool.
Such long-felt needs have been particularly prevalent in the field of endoscopic surgical instruments that are used in minimally invasive surgical procedures. These types of procedures are performed through one, two, three, or even four small incisions created in the skin of a patient. In multiple incision procedures, a single endoscopic instrument may be introduced per incision. Each such instrument can be manipulated from the exterior of the patient to remotely conduct a specific surgical operation inside the patient. To lessen the trauma to the patient, it is preferable to minimize the number of such incisions and surgical instruments.
The procedure can involve a relatively non-complex procedure such as a biopsy, as well as complicated cardiothoracic remedial and interventional operations. In the latter, one or more endoscopic tools are needed to perform the procedure and space inside the body of the patient is at a premium. Therefore, any tools that are to be introduced into the surgical field must compete for space with other tools including for example, clamps, cutting tools, fluid injection and suction ports, lighting and visual equipment, and similar devices. Accordingly, those with skill in the art can appreciate that there is limited intracorporeal space available for tools and equipment. Therefore, before one tool can be introduced, another tool may have to be removed. Since only a limited number of minimally invasive type endoscopic surgical instruments are preferably utilized during any given procedure, there has long been a need for the capability to interchange multiple surgical tools on any single endoscopic instrument.
The removability and interchangeability of the tools and reusability of such surgical instrument can reduce costs and complexity. For example, maintenance costs associated with refurbishment, cleaning, and sharpening tools after each surgical procedure is significant. Removable end tools can facilitate such efforts and can also be adapted for single use applications, which eliminates the need for cleaning and refurbishment. During use, tissue and fluids become lodged in the crevices and interstices of small surgical instruments, which complicate sterilization and refurbishment.
Furthermore, the means for connecting the removable tool to the manipulation shaft of the surgical instrument is important to the usefulness of the surgical instrument. The connection must positively secure the components together during operation, and must maintain the connection throughout the range of motion forces typically encountered during surgical procedures. The connection must allow the smooth and controllable transfer of motion from an actuation shaft to the surgical tool. The connection must also facilitate quick and easy connection and disconnection of the interchangeable tool. The connection must be such that it does not become loose and allow movement between the components after repeated use. Further, a connection incorporating a predetermined failsafe mode is desired. The connection should facilitate the transfer of electrical current for certain procedures, while the tool should incorporate electrical insulating properties in those areas necessary to prevent accidental energy transfer to surrounding tissues.
Many attempts have been made to create reconfigurable endoscopic instruments that can employ a variety of surgical tools. One such attempt is a medical instrument that incorporates a handle having scissor grips adapted to actuate a manipulation shaft that is connected to the interchangeable tool, which may be, for example, a grasper, biopsy collector, dissector, or scissor.
Other attempts aimed at reducing maintenance expenses of surgical tools are exemplified by, among other patents, U.S. Pat. No. 4,569,131 to Falk et al. The Falk et al. instrument is a device that has a handle and jaws that are separable from an instrument shaft so that the individual components may be more easily cleaned and sharpened, or disposed of after each use.
Surgical instruments such as that described in U.S. Pat. No. 5,618,303 to Marlowe et al. have attempted to improve joints between components of the instruments. Marlowe et al. discloses a device that includes a stub shaft or link means terminating in an enlarged end that is shaped to be received by a clevis. Other types of joints are described in U.S. Pat. No. 5,304,203 to El-Mallawany et al., which teaches a T-shaped coupling joint.
Likewise, surgeons have long appreciated that complex surgical devices should have built-in failsafe modes so that the patient is not injured if the device should fail. U.S. Pat. No. 5,275,607 to Lo et al. describes such a device directed to intraocular surgery. The '607 device is designed such that if the power fails during surgery the surgeons can manually override the system so that the blades may be closed and the tool removed from the eye. Such a desirable predetermined failsafe mode, preferential mode of failure, or directed point of failure, in some cases, is lacking from the field of reconfigurable surgical instruments.
What continues to be needed but missing from the field of interchangeable surgical tools is a secure connection between components that will not loosen after several uses, which is also designed for improved ease of manufacture and replaceability. While some of the prior art devices attempted to improve the state of the art of interchangeable surgical tools, none has achieved low cost parts that are easy to fabricate and convenient to use. A more desirable interchangeable surgical tool preferably includes a more secure connection, which can be adapted so that different tools can be configured to the surgical instrument. Even more desirable is a tool with a built in predetermined failsafe mode to minimize the chance of patient injury, facilitates selective cauterization, and minimizes the likelihood of damage to surrounding tissue. With these capabilities taken into consideration, the instant invention addresses many of the shortcomings of the prior art and offers significant benefits heretofore unavailable.